The Oracle says the truce has to come from the bottom up -- basically, that people can't be ordered by their superiors or their governments to get along. The people themselves have to want it.
I want there to be peace. I really do. But I've seen such intense hatred towards the Machines from so many Zionites...hatred, and the desire for revenge for their ancestors' 'enslavement' -- which I see more as the way the human race was saved from the extinction that claimed most of the species of this world. (The way I see it, being angry at the Machines for winning the original war so many years ago and being in charge now would be like me being angry that my British ancestors were conquered by the Anglo-Saxons and that I, centuries later, am speaking English instead of a Celtic language.)
I understand the need for security and defense, and that the citizens of New Zion want to feel safe. Some say that's the only reason why that city was built, and I'm sure they believe that's true. But given the hatred I've seen, I truly believe that some in New Zion would use that city as a safe base to retreat to after acts of terrorism against the Matrix and the Machines. Even before this safe haven was built, Cryptos once hated the Machines so much he would have killed millions of people with nuclear weapons just to spite them. And right now I'm terrified that this sort of thing could actually happen...whether it be at the hands of a few fanatics or as a result of an attack officially sanctioned by New Zion's leadership. This is more likely to occur now because those in New Zion won't have to fear any reprisals against their city.
Machinists want peace. We want potentials to be allowed to be awakened again. But even before the truce ended, in the earliest Machine mission we were given, we hear Zionites calling for the deaths of those who left them to work with the Machines. We don't know how many people in New Zion harbor this hatred against the Machines (and against those of us who work with them), and how far that hatred will drive them, especially now that they don't have to worry about a Machine attack if they decide to act on that hatred.
Illyria